Evaluating the Ethos automated planning system for spatially fractionated radiotherapy

IF 2.2 4区医学 Q3 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Journal of Applied Clinical Medical Physics Pub Date : 2025-10-10 DOI:10.1002/acm2.70306

A Aziz Sait, Yoganathan SA, Amine Khemissi, Umang Patel, Sunil Mani, Satheesh Paloor, Rabih Hammoud

{"title":"Evaluating the Ethos automated planning system for spatially fractionated radiotherapy","authors":"A Aziz Sait, Yoganathan SA, Amine Khemissi, Umang Patel, Sunil Mani, Satheesh Paloor, Rabih Hammoud","doi":"10.1002/acm2.70306","DOIUrl":null,"url":null,"abstract":"<div>\n \n \n <section>\n \n <h3> Purpose</h3>\n \n <p>Lattice radiotherapy (LRT), a form of spatially fractionated radiation therapy (SFRT), has emerged as a promising approach for treating massive tumors. By delivering high-dose regions within the tumor while sparing surrounding healthy tissue, LRT offers distinct advantages over conventional radiotherapy. Recent advancements in treatment planning systems (TPS), particularly the integration of intelligent optimization engines (IOEs) with automated planning capabilities, have the potential to further refine and expand the clinical utility of LRT. This study aimed to comparatively evaluate the planning quality and clinical feasibility of lattice SFRT treatment plans generated using the Ethos planning system, equipped with an IOE and O-ring linear accelerator, versus the Eclipse planning system paired with a conventional C-arm TrueBeam linac, in patients with stage III non-small cell lung cancer (NSCLC).</p>\n </section>\n \n <section>\n \n <h3> Methods</h3>\n \n <p>Twenty retrospective stage III NSCLC cases (GTV > 200 cc) with available PET-CT imaging were selected. A total of 40 plans (20 Eclipse, 20 Ethos) were compared, incorporating lattice spheres (1 cm diameter, 2 cm spacing between spheres) placed in the tumor, FDG-PET/CT-informed intratumoral heterogeneity, prioritizing viable perinecrotic subregions while avoiding critical OARs. Plans aimed to deliver 15 Gy to lattice spheres, limit Valley (PTV minus spheres) doses to 2 Gy, and restrict doses to organs at risk (OARs) to ≤ 3 Gy. Dose conformity, OAR sparing, dose gradient parameters (PEDR, PVDR), planning time, and deliverability, which was evaluated using ArcCheck, EPID gamma analysis, and MLC log-file verification.</p>\n </section>\n \n <section>\n \n <h3> Results</h3>\n \n <p>Ethos demonstrated statistically significant improvements compared to Eclipse in lattice sphere mean dose (17.2 Gy vs. 15.83 Gy, <i>p</i> < 0.001), V15 Gy coverage (98.2 % vs. 91.74 %, <i>p</i> < 0.001), and dose gradient metrics (PEDR: 6.42 vs. 5.80; PVDR: 3.70 vs. 3.29; both <i>p</i> < 0.001, and VPDR: 0.131 vs. 0.135; PVDR<sub>DVH</sub>: 7.62 vs. 7.41). For the valley target, Ethos plans demonstrated a lower mean dose (Dmean: 4.72 Gy vs. 4.91 Gy, <i>p</i> = 0.064), although not statistically significant, and achieved significantly improved dose gradient at V7.5 Gy (14.5% vs. 16.35%, <i>p</i> = 0.019), V5Gy (30.77% vs. 34.84%, <i>p</i> = 0.006), and V2Gy (99.77% vs. 97.79%, <i>p</i> < 0.001) compared to Eclipse. Ethos achieved significantly better OAR sparing, particularly for the bronchial tree, heart, spinal cord, esophagus, and great vessels (all <i>p</i> < 0.01). Furthermore, Ethos substantially reduced planning time (36.55 vs. 95.96 min, <i>p</i> < 0.001). Both planning systems achieved high gamma passing rates (> 95%), confirming the accuracy and deliverability of the treatment plans.</p>\n </section>\n \n <section>\n \n <h3> Conclusion</h3>\n \n <p>The Ethos automated treatment planning demonstrated superior lattice dose conformity, enhanced OAR sparing, and significantly faster optimization compared to Eclipse. This automated optimization capability highlights the potential of Ethos for efficient and effective lattice radiotherapy in managing massive NSCLC tumors.</p>\n </section>\n </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 10","pages":""},"PeriodicalIF":2.2000,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70306","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Applied Clinical Medical Physics","FirstCategoryId":"3","ListUrlMain":"https://aapm.onlinelibrary.wiley.com/doi/10.1002/acm2.70306","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}

引用次数: 0

Abstract

Purpose

Lattice radiotherapy (LRT), a form of spatially fractionated radiation therapy (SFRT), has emerged as a promising approach for treating massive tumors. By delivering high-dose regions within the tumor while sparing surrounding healthy tissue, LRT offers distinct advantages over conventional radiotherapy. Recent advancements in treatment planning systems (TPS), particularly the integration of intelligent optimization engines (IOEs) with automated planning capabilities, have the potential to further refine and expand the clinical utility of LRT. This study aimed to comparatively evaluate the planning quality and clinical feasibility of lattice SFRT treatment plans generated using the Ethos planning system, equipped with an IOE and O-ring linear accelerator, versus the Eclipse planning system paired with a conventional C-arm TrueBeam linac, in patients with stage III non-small cell lung cancer (NSCLC).

Methods

Twenty retrospective stage III NSCLC cases (GTV > 200 cc) with available PET-CT imaging were selected. A total of 40 plans (20 Eclipse, 20 Ethos) were compared, incorporating lattice spheres (1 cm diameter, 2 cm spacing between spheres) placed in the tumor, FDG-PET/CT-informed intratumoral heterogeneity, prioritizing viable perinecrotic subregions while avoiding critical OARs. Plans aimed to deliver 15 Gy to lattice spheres, limit Valley (PTV minus spheres) doses to 2 Gy, and restrict doses to organs at risk (OARs) to ≤ 3 Gy. Dose conformity, OAR sparing, dose gradient parameters (PEDR, PVDR), planning time, and deliverability, which was evaluated using ArcCheck, EPID gamma analysis, and MLC log-file verification.

Results

Ethos demonstrated statistically significant improvements compared to Eclipse in lattice sphere mean dose (17.2 Gy vs. 15.83 Gy, p < 0.001), V15 Gy coverage (98.2 % vs. 91.74 %, p < 0.001), and dose gradient metrics (PEDR: 6.42 vs. 5.80; PVDR: 3.70 vs. 3.29; both p < 0.001, and VPDR: 0.131 vs. 0.135; PVDR_DVH: 7.62 vs. 7.41). For the valley target, Ethos plans demonstrated a lower mean dose (Dmean: 4.72 Gy vs. 4.91 Gy, p = 0.064), although not statistically significant, and achieved significantly improved dose gradient at V7.5 Gy (14.5% vs. 16.35%, p = 0.019), V5Gy (30.77% vs. 34.84%, p = 0.006), and V2Gy (99.77% vs. 97.79%, p < 0.001) compared to Eclipse. Ethos achieved significantly better OAR sparing, particularly for the bronchial tree, heart, spinal cord, esophagus, and great vessels (all p < 0.01). Furthermore, Ethos substantially reduced planning time (36.55 vs. 95.96 min, p < 0.001). Both planning systems achieved high gamma passing rates (> 95%), confirming the accuracy and deliverability of the treatment plans.

Conclusion

The Ethos automated treatment planning demonstrated superior lattice dose conformity, enhanced OAR sparing, and significantly faster optimization compared to Eclipse. This automated optimization capability highlights the potential of Ethos for efficient and effective lattice radiotherapy in managing massive NSCLC tumors.

Abstract Image

查看原文本刊更多论文

对Ethos空间分割放疗自动规划系统的评价

点阵放射治疗（LRT）是空间分割放射治疗（SFRT）的一种形式，已成为治疗巨大肿瘤的一种很有前途的方法。通过在肿瘤内提供高剂量区域，同时保留周围的健康组织，轻放射治疗比传统放射治疗具有明显的优势。治疗计划系统（TPS）的最新进展，特别是智能优化引擎（ioe）与自动计划能力的集成，有可能进一步完善和扩大LRT的临床应用。本研究旨在比较评估在III期非小细胞肺癌（NSCLC）患者中，使用配备IOE和o型环直线加速器的Ethos计划系统与使用常规c臂TrueBeam直线加速器的Eclipse计划系统生成的点阵SFRT治疗计划的计划质量和临床可行性。方法回顾性分析具有PET-CT显像的III期非小细胞肺癌（GTV > 200cc）病例20例。共比较了40种方案（20种为Eclipse， 20种为Ethos），将晶格球（直径1厘米，球间距2厘米）放置在肿瘤中，FDG-PET/ ct提示肿瘤内异质性，优先考虑可行的会阴亚区，同时避免关键的划水。计划旨在向晶格球输送15 Gy，将谷（PTV减去球）剂量限制在2 Gy，并将危及器官（OARs）的剂量限制在≤3 Gy。剂量符合性、OAR节约、剂量梯度参数（PEDR、PVDR）、计划时间和可交付性，通过ArcCheck、EPID伽马分析和MLC日志文件验证进行评估。结果与Eclipse相比，Ethos在晶格球平均剂量（17.2 Gy vs. 15.83 Gy, p < 0.001）， V15 Gy覆盖率（98.2% vs. 91.74%, p < 0.001）和剂量梯度指标（PEDR: 6.42 vs. 5.80; PVDR: 3.70 vs. 3.29; p < 0.001, VPDR: 0.131 vs. 0.135; PVDRDVH: 7.62 vs. 7.41）方面表现出统计学上的显著改善。对于谷靶，Ethos计划显示出较低的平均剂量（Dmean: 4.72 Gy vs. 4.91 Gy, p = 0.064），尽管没有统计学意义，但与Eclipse相比，在V7.5 Gy （14.5% vs. 16.35%, p = 0.019）、V5Gy （30.77% vs. 34.84%, p = 0.006）和V2Gy （99.77% vs. 97.79%, p < 0.001）的剂量梯度显著改善。Ethos取得了显著更好的桨叶节约效果，尤其是支气管树、心脏、脊髓、食道和大血管（p < 0.01）。此外，Ethos大大减少了计划时间（36.55分钟vs. 95.96分钟，p < 0.001）。两种计划系统均获得了较高的伽马通过率（95%），证实了治疗计划的准确性和可交付性。与Eclipse相比，Ethos自动化治疗计划具有更好的晶格剂量一致性，增强了OAR保留，优化速度明显加快。这种自动优化能力突出了Ethos在治疗大面积非小细胞肺癌肿瘤中高效和有效的点阵放疗的潜力。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of Applied Clinical Medical Physics 医学-核医学

CiteScore

3.60

自引率

19.00%

发文量

331

审稿时长

3 months

期刊介绍： Journal of Applied Clinical Medical Physics is an international Open Access publication dedicated to clinical medical physics. JACMP welcomes original contributions dealing with all aspects of medical physics from scientists working in the clinical medical physics around the world. JACMP accepts only online submission. JACMP will publish: -Original Contributions: Peer-reviewed, investigations that represent new and significant contributions to the field. Recommended word count: up to 7500. -Review Articles: Reviews of major areas or sub-areas in the field of clinical medical physics. These articles may be of any length and are peer reviewed. -Technical Notes: These should be no longer than 3000 words, including key references. -Letters to the Editor: Comments on papers published in JACMP or on any other matters of interest to clinical medical physics. These should not be more than 1250 (including the literature) and their publication is only based on the decision of the editor, who occasionally asks experts on the merit of the contents. -Book Reviews: The editorial office solicits Book Reviews. -Announcements of Forthcoming Meetings: The Editor may provide notice of forthcoming meetings, course offerings, and other events relevant to clinical medical physics. -Parallel Opposed Editorial: We welcome topics relevant to clinical practice and medical physics profession. The contents can be controversial debate or opposed aspects of an issue. One author argues for the position and the other against. Each side of the debate contains an opening statement up to 800 words, followed by a rebuttal up to 500 words. Readers interested in participating in this series should contact the moderator with a proposed title and a short description of the topic